Technical Abstract:
Four wheat (Triticum aestivum) fungal resistance genes/QTL have been localized to the region on chromosome 3BS between the markers Xgwm493 and Xgwm389. The durable stem rust (caused by Puccinia graminis) resistance gene Sr2, Fusarium head blight (caused by Fusarium graminearum) resistance QTL Qfhs.ndsu-3BS, Septoria tritici blotch (caused by Mycosphaerella graminicola) resistance gene Stb2, and Stagonospora blotch (caused by Stagonospora nodorum) resistance QTL QSng.sfr-3BS are all in current cultivars, but the tight repulsion linkage will require recombination events to occur. The initiative to build a 3BS linkage block with all four traits is in progress. Crosses were made between the stem rust resistant parent Ocoroni 86 and the Fusarium head blight resistant cultivar Alsen. Additionally crosses were made between the Septoria tritici blotch resistant parent DH 115 and the Stagonospora blotch resistant cultivar Arina. Recombinant stem rust and Fusarium head blight resistant and susceptible phenotypes were observed in F2 and verified in F5 from the cross of Ocoroni 86 x Alsen. The phenotypic marker for Sr2, pseudo-black chaff, and DNA markers Xgwm533 and Xgwm493 were also used to assist in the selection of Sr2 and Qfhs.ndsu-3BS for recombinant plants. Recombinant plants resistant to both Septoria tritici blotch and Stagonospora blotch from the cross of DH 115 x Arina were observed in F2 and F3 and will be verified in the F4 plants. Respective resistant recombinant plants will be crossed in order to develop plants with resistance to all four diseases.